1. Field of the Invention
The present invention relates to hyperlinking multimedia documents and more particularly to a synthesis process of constructing semantic media structures for all different media in media documentation.
2. Description of the Prior Art
In the recent years, hypermedia has become increasingly important in many applications, ranging from browsing of consumer-type information over Internet, to learning serious subjects such as mathematics and science, and to retrieving important technical documents for engineering purposes. Typically, documents in different media (including text, graphical images, schematic diagrams, CAD drawings, audio, video, etc.) are identified and linked together manually so that, when browsing one document, related documents can be easily retrieved. Since textual documents are usually represented in the ASCII format, further processing can be performed manually or automatically to identify words and phrases to be linked to other textual and non-textual documents. In addition, by using a markup language such as SGML (SGML, ISO 8879:1986 Text and Office Systems--Standard Generalized Markup Language, Geneva, 1986), textual documents can be structured semantically for a specific application domain and can be processed and linked more precisely to other textual and non-textual documents automatically. This is described by Peiya Liu, Ken Hampel, and Arding Hsu in "Towards Automating the Creation of Hypermedia Service Manuals by Compiling Specifications", Proc. of Intl Conf. on Multimedia Computing and Systems, IEEE Computing Soc. Press, 1994., pp. 203-212.
Processing of non-textual documents, however, has not been as successful because the representation of non-textual documents is often in bit and byte sequences and optionally with complex compression schemes, which provide very limited semantic information of the subject matter. In order to make better use of non-textual documents in hypermedia applications, graphics and image processing techniques are often applied to manipulate and extract relevant information from these types of media. In general, pieces of information that can be identified precisely (and extracted manually or automatically) in textual or non-textual media are referred to as AIU's (Anchorable Information Units). AIU's can be used to relate to one another in the same document or between two different documents.
State-of-the-art graphics and image processing techniques are often developed in very specific application domains such as medical imaging, OCR (Optical Character Recognition) in document processing. Some of the techniques have been modified and applied to extracting AIU's in non-textual media such as schematic diagrams and CAD drawings for technical documents. These approaches represent the first step towards the automated process of extracting information. However, they basically deal with only raw text and polylines, which are not sufficient to support more precise hyperlinking for various technical tasks such as inspection, maintenance, troubleshooting, etc.